LintCode 401. Kth Smallest Number in Sorted Matrix

http://www.lintcode.com/en/problem/kth-smallest-number-in-sorted-matrix/



Find the kth smallest number in at row and column sorted matrix.
Example
Given k = 4 and a matrix:
[
[1 ,5 ,7],
[3 ,7 ,8],
[4 ,8 ,9],
]
return 5

LeetCode 779. K-th Symbol in Grammar - Weekly Contest 70

https://leetcode.com/contest/weekly-contest-70/problems/k-th-symbol-in-grammar/

LeetCode 771. Jewels and Stones - Weekly Contest 69

https://leetcode.com/contest/weekly-contest-69/problems/jewels-and-stones/

LeetCode 775. Global and Local Inversions - Weekly Contest 69

https://leetcode.com/contest/weekly-contest-69/problems/global-and-local-inversions/

LeetCode 159. Longest Substring with At Most Two Distinct Characters - Google - HashMap, Two Pointers, String

The main idea is to maintain a sliding window with 2 unique characters. 

The key is to store the last occurrence of each character as the value in the hashmap.

https://leetcode.com/problems/longest-substring-with-at-most-two-distinct-characters/description/

LeetCode 768. Max Chunks to Make Sorted (ver. 2) - Weekly Contest 68

https://leetcode.com/contest/weekly-contest-68/problems/max-chunks-to-make-sorted-ver-2/

LeetCode 769. Max Chunks To Make Sorted (ver. 1) - Weekly Contest 68

https://leetcode.com/contest/weekly-contest-68/problems/max-chunks-to-make-sorted-ver-1/